build_request raises raw httpx2.InvalidURL while every other entry point maps it #175

Since 0.22.0, an invalid URL passed to a verb method, request() or a *_with_response method raises TransportError, with the httpx2.InvalidURL as __cause__. Client.build_request and AsyncClient.build_request still raise the raw httpx2.InvalidURL:

import httpware

httpware.Client().build_request("GET", "https://example.test/\x00")
# httpx2.InvalidURL

build_request delegates straight to httpx2, and ADR-0008 makes httpx2 public surface, so the raw error may be the intended behaviour here. Either map it like the other entry points or say in the docstring that build_request raises httpx2 errors.